Core biopsy and fine needle aspiration (FNA)

1. What are core biopsies and FNAs for?

Sometimes a small sample of breast cells or breast tissue may be taken to help make a diagnosis. This will usually be done using a core biopsy. Sometimes a fine needle aspiration (FNA) or another procedure, such as a punch biopsy, may be used. The sample is then sent to the laboratory where it is looked at under a microscope.

A mammogram or ultrasound may be used as a guide to pinpoint the area before the sample is taken, particularly when it’s very small or cannot be felt.

If you’re taking aspirin or any anticoagulants (blood-thinning tablets), let the doctor know before having a core biopsy or an FNA.

Having a core biopsy or an FNA doesn’t necessarily mean you have breast cancer.

2. Core biopsy (also called core needle biopsy)

A core biopsy uses a hollow needle to get a sample of breast tissue. Because tissue is taken rather than cells, it gives more detailed information. Several tissue samples may be taken at the same time.

After local anaesthetic is given to numb the area, a small cut is made in the skin so that samples of tissue can be taken. Sometimes you’ll be asked to lie on your front while this is done.

If the area of concern can only be seen on a mammogram, you may have a stereotactic core biopsy. This is where a sample of tissue is taken using a needle biopsy device connected to a mammogram machine and linked to a computer. This helps locate the exact position of the area to be biopsied. Images of the breast are taken from two different angles to help guide the needle to the precise location.

You will be given a local anaesthetic and will be in a sitting position or lying down on a specialised examination couch. It may feel a little uncomfortable as the mammogram plates are pressed onto the breast throughout.

Whichever way the core biopsy is done, a small dressing or plaster will usually be applied, and you’ll be asked to keep this on for a day or so afterwards. Sometimes very thin strips of adhesive tape are used to help the edges of the wound to close.

Once the local anaesthetic wears off, your breast may ache and may be bruised for the next few days or weeks. You can take pain relief if the area is tender or painful. You’ll be given more information about this before you leave the clinic.

3. Fine needle aspiration (FNA)

FNA uses a fine needle and syringe to take a sample of cells. Occasionally, local anaesthetic is used first to numb the area. You may be asked to wear a plaster for a few hours over the site where the needle has been inserted.

4. Punch biopsy

A punch biopsy may be done when there is a change to the skin of the breast or nipple. It involves taking a very small cylindrical piece of tissue from the changed area. You will be given a local anaesthetic before a tiny cutting device is used to take the sample. As with a core biopsy, you’ll usually be asked to wear a small dressing or plaster afterwards.

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